1. Technical Field
Embodiments of the present disclosure are directed to a top emission device and an organic light-emitting diode display device, and more particularly, to a top emission device and a top emission type organic light-emitting diode display device emitting light mainly to a front surface thereof.
2. Discussion of the Related Art
Light emitting devices, which are devices that provide light, are used in the fields of lightings or displays. For example, an organic light-emitting diode display device can include a plurality of organic light-emitting devices and can control the amount of light emitted from the respective organic light-emitting devices to display an image. A light emitting layer of a organic light-emitting device emits light through two surfaces thereof, and if a screen is viewed in one direction, the device may be provided with a reflective electrode or a reflective layer to reflect light emitted therefrom in a screen display direction.
A case in which an organic light-emitting device is disposed in front of a substrate, and light is emitted in a direction toward the substrate is commonly referred to as 'bottom emission, while a case in which light is emitted in a front direction that is opposite to the direction toward the substrate is commonly referred to as ‘top emission’. A bottom emission type organic light-emitting diode display device may employ a top electrode of an organic light-emitting device as a reflective electrode to emit light to a rear surface thereof. On the other hand, a top emission type organic light-emitting diode display device may include a reflective electrode or a reflective layer in a lower electrode of an organic light-emitting device.
In addition, a degree of degradation in an organic light-emitting diode display device may vary depending on how much current accumulates in each pixel. If degradation has been detected so that the current provided to a corresponding pixel can be compensated, deterioration of image quality due to the degradation may be prevented. To this end, the luminance of emitted light should be determined.
For a bottom emission type display device, since light that is laterally leaking may be reflected from the interior of a display panel and may propagate laterally through the display panel, light emitted from pixels may be detected when an light sensor is provided on a side surface of the display panel. On the basis of this, a pixel light emission intensity can be estimated. However, for a top emission type display device, since a transparent electrode or a translucent electrode is used as a top electrode, the intensity of laterally propagating light may be low. Thus, even if a light sensor is installed on a side surface of the display panel, it may not precisely detect and estimate the light intensity emitted from the pixels.